Oxygen management in mechanically ventilated patients: A multicenter prospective observational study

Purpose: To observe arterial oxygen in relation to fraction of inspired oxygen (F_IO₂) during mechanical ventilation (MV). Materials and methods: In this multicenter prospective observational study, we included adult patients required MV for >48 h during the period from March to May 2015. We obtained F_IO₂, PaO₂ and SaO₂ from commencement of MV until the 7th day of MV in the ICU. Results: We included 454 patients from 28 ICUs in this study. The median APACHE II score was 22. Median values of F_IO₂, PaO₂ and SaO₂ were 0.40, 96 mm Hg and 98%. After day two, patients spent most of their time with a F_IO₂ between 0.3 and 0.49 with median PaO₂ of approximately 90 mm Hg and SaO₂ of 97%. PaO₂ was ≥100 mm Hg during 47.2% of the study period and was ≥130 mm Hg during 18.4% of the study period. F_IO₂ was more likely decreased when PaO₂ was ≥130 mm Hg or SaO₂ was ≥99% with a F_IO₂ of 0.5 or greater. When F_IO₂ was <0.5, however, F_IO₂ was less likely decreased regardless of the value of PaO₂ and SaO₂. Conclusions: In our multicenter prospective study, we found that hyperoxemia was common and that hyperoxemia was not corrected.